Riddle #1

Here is a little riddle for you… no more then 30 seconds to answer :)

 mov ecx, 0Ch
 mov dl, 1h
 mov dh, 1h
 L:
  xchg dh, dl
  add dl, dh
  movzx eax, dl
  loop L

Try to figure out what the code above is intended for, and let me know…

Enjoy ;)

~~p.s. Are you thinking about a bug? Well, it’s not a bug.~~

Donato "ratsoul" Ferrante posted at 2009-12-7 Category: fun, reversing, riddle

#1rastaganga @ 2009-12-8 11:23

The pseudo code:
```
  a = 1
  b = 1

  for(i = 12; i--; i==1) {
    b = a
    a = b + a
  }
```
I’m not sure what the code is ‘intended for’. For me it just looks like a weird loop :)
#2ratsoul @ 2009-12-9 11:19

Hi rastaganga,

thank you for your answer. I will say more about this riddle in the following days, now may be someone else want to play with it, so I don’t want to spoil ;)
#3dreyercito @ 2009-12-9 16:28

Seems a fibonacci sequence calculator. Fibonacci(ecx) (for iterations of n>1). Am I right? Do I get a lollipop?
#4ratsoul @ 2009-12-9 17:21

Hi dreyercito,

your answer hit the solution but it is not 100% right. You are missing something…

So no lollipop for you dude ;)
#5vsw0rd @ 2010-1-6 09:56

2^12